The present invention relates to an apparatus and a method for removing fine metal particles and the like from a cutting oil used in cutting aluminum or the like, for example, for aircraft materials. More particularly, the present invention relates to an apparatus and a method for electrochemically removing fine metal particles from an emulsion to clean cutting oil.
Conventionally, when an aluminum alloy workpiece to be cut is machined into a desired shape using a cutting machine, cutting oil has been used for cooling the workpiece at the cutting location and for imparting fluidity to the metal chips. An emulsion of oil in water having a water:oil mixing ratio of 95:5 is mainly used.
To reuse the emulsion, fine metal particles, grease and lubricating oil are removed. According to the conventional removal operation, the used emulsion is subjected to centrifugation or filtration.
However, the fine metal particles have extremely small diameters, and further, the difference in the specific gravity between water and the fine metal particles, particularly of aluminum, contained in the cutting oil subjected to centrifugation is not large. Therefore, water and fine metal particles cannot be fully separated from each other by means of centrifugation. Meanwhile, when the emulsion is subjected to filtration, the fine metal particles that have very small diameters pass through the filter. Therefore, the fine metal particles contained in the emulsion cannot be removed completely.
Further, when a filter is used in the removal of fine metal particles, the fine metal particles clog the filter, and maintenance is needed.
It is a first object of the present invention to provide an apparatus and a method for removing electrochemically fine metal particles in an emulsion to clean and reuse the emulsion.
It is a second object of the present invention to provide an apparatus and a method for removing fine metal particles that reduce maintenance requirements and facilitates removal of fine metal particles.
To achieve the above objects, the present invention provides an apparatus for electrochemically removing fine metal particles in an oil and water emulsion. The apparatus includes a container for accommodating the oil in water emulsion. A supply port supplies the emulsion to the container. A plurality of cathode plates and anode plates are located in the container to face each other. The water in the emulsion is electrolyzed when a predetermined direct voltage is applied between each anode plate and each cathode plate. The fine metal particles along with sludge, greese and lubricating oil which is the main odor float with hydrogen generated by the electrolysis. A discharge port is located in the lower part of the container, and the oil in water emulsion is discharged without the metal particles.
The present invention also provides an electrochemical removing method for removing fine metal particles. The method includes supplying an oil in water emulsion to a container from a supply port on the container, supplying the emulsion between a plurality of anode plates and cathode plates located in the container to face each other, applying a predetermined direct voltage to the emulsion to electrolyze water in the emulsion and to remove the fine metal particles with hydrogen generated from the anode plate by the electrolysis, and discharging the emulsion, from which the fine metal particles have been removed, from the discharge port.
Other aspects and advantages of the invention will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.